9-21974861-C-A
Variant summary
Our verdict is Likely pathogenic. Variant got 7 ACMG points: 8P and 1B. PP5_Very_StrongBP4
The ENST00000498124.1(CDKN2A):โc.-34G>T variant causes a 5 prime UTR premature start codon gain change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000603 in 1,509,400 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Pathogenic (โ โ ).
Frequency
Consequence
ENST00000498124.1 5_prime_UTR_premature_start_codon_gain
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Likely_pathogenic. Variant got 7 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000131 AC: 2AN: 152180Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.0000433 AC: 5AN: 115386Hom.: 0 AF XY: 0.0000474 AC XY: 3AN XY: 63326
GnomAD4 exome AF: 0.0000656 AC: 89AN: 1357220Hom.: 0 Cov.: 31 AF XY: 0.0000523 AC XY: 35AN XY: 668658
GnomAD4 genome AF: 0.0000131 AC: 2AN: 152180Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0AN XY: 74352
ClinVar
Submissions by phenotype
not provided Pathogenic:5
CDKN2A: PP1:Strong, PM2, PS3:Moderate, PS4:Moderate -
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Describes a nucleotide substitution 34 base pairs upstream of the ATG translational start site of the CDKN2A gene that creates an aberrant ATG translation initiation codon; Published functional studies demonstrate a damaging effect: decreases translation from the wild-type ATG and results in a truncated protein that significantly affects reporter activity (PMID: 9916806, 20093296); Nucleotide substitution has no predicted effect on splicing and is not conserved across species; This variant is associated with the following publications: (PMID: 26557774, 26775776, 19523171, 16896043, 25780468, 9916806, 20093296, 26581427, 26681309, 26099287, 12072543, 26681312, 16397522, 16905682, 15146471, 28495237, 29263814, 28830827, 30067863, 30117292, 30113427, 31567591, 33077847, 32482799, 34598035, 17713569, 29922827) -
The CDKN2A c.-34G>T variant has been reported in the published literature in functional studies that indicate this variant creates an out of frame translation initiation codon that results in a truncated protein and decreases translation from the wild-type start site. The variant also had a negative impact on transcriptional activity in a luciferase reporter assay (PMIDs: 9916806 (1999) and 20093296 (2010)). In addition, the variant has been reported in multiple individuals and families affected with familial melanoma (PMIDs: 16397522 (2006), 17713569 (2008), 19523171 (2009), 25780468 (2014), 26681309 (2016), 26775776 (2016), and 31567591 (2020)), and showed a strong co-segregation with disease (PMIDs: 9916806 (1999) and 10738302 (2000)). The frequency of this variant in the general population, 0.000075 (5/66812 chromosomes (Genome Aggregation Database, http://gnomad.broadinstitute.org)), is uninformative in the assessment of its pathogenicity. Based on the available information, this variant is classified as pathogenic. -
The CDKN2A c.-34G>T variant (rs1800586; ClinVar ID: 182414) is reported in the literature in multiple individuals affected with melanoma and/or pancreatic cancer and has been demonstrated to co-segregate with disease in multiple families (Andreotti 2016, Ashton-Prolla 2008, Bran 2018, Liu 1999, Overbeek 2021, Taylor 2017). This variant is found in the general population with a low overall allele frequency of 0.004% (6/146,754 alleles) in the Genome Aggregation Database (v2.1.1). This variant occurs in the 5รขโฌโข untranslated region of the CDKN2A gene and is predicted to create a novel initiation codon that results in a truncated protein (Liu 1999). Functional analysis in multiple cell lines suggests the variant is associated with significantly reduced expression from the canonical initiation codon (Liu 1999, Andreotti 2016, Bisio 2010). Based on available information, this variant is considered to be pathogenic. References: Andreotti V et al. The CDKN2A/p16(INK) (4a) 5'UTR sequence and translational regulation: impact of novel variants predisposing to melanoma. Pigment Cell Melanoma Res. 2016 Mar;29(2):210-21. PMID: 26581427. Ashton-Prolla P et al. Clinical and molecular characterization of patients at risk for hereditary melanoma in southern Brazil. J Invest Dermatol. 2008 Feb;128(2):421-5. PMID: 17713569. Bisio A et al. Functional analysis of CDKN2A/p16INK4a 5'-UTR variants predisposing to melanoma. Hum Mol Genet. 2010 Apr 15;19(8):1479-91. PMID: 20093296. Brand R et al. Prospective study of germline genetic testing in incident cases of pancreatic adenocarcinoma. Cancer. 2018 Sep 1;124(17):3520-3527. PMID: 30067863. Liu L et al. Mutation of the CDKN2A 5' UTR creates an aberrant initiation codon and predisposes to melanoma. Nat Genet. 1999 Jan;21(1):128-32. PMID: 9916806. Overbeek KA et al. Genotype-phenotype correlations for pancreatic cancer risk in Dutch melanoma families with pathogenic CDKN2A variants. J Med Genet. 2021 Apr;58(4):264-269. PMID: 32482799. Taylor NJ et al. Germline Variation at CDKN2A and Associations with Nevus Phenotypes among Members of Melanoma Families. J Invest Dermatol. 2017 Dec;137(12):2606-2612. PMID: 28830827. -
Melanoma-pancreatic cancer syndrome Pathogenic:2
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Hereditary cancer-predisposing syndrome Pathogenic:2
The c.-34G>T pathogenic mutation is located in the 5' untranslated region (5'UTR) of the CDKN2A gene. This mutation results from a G to T substitution 34 nucleotides upstream from the first translated codon. This sequence alteration creates a potential AUG initiation codon at base -35 and translation initiation from this novel start site predicts a truncated protein with no homology to wild type (Liu L et al. Nat. Genet. 1999 Jan;21:128-32). Functional studies demonstrate that the c.-34G>T mutation severely reduces the reporter activity in every cell type tested (Bisio A et al. Hum. Mol. Genet. 2010 Apr;19:1479-91). This alteration was identified in an individual with at least 3 primary melanoma diagnoses (Li C et al. Melanoma Res. 2020 06;30:247-251). In addition, this alteration has been reported in numerous families with melanoma, pancreatic cancer, and/or atypical nevi, and has been shown to segregate with disease (Liu L et al. Nat. Genet. 1999 Jan;21:128-32; Berwick M et al. Cancer Epidemiol. Biomarkers Prev. 2006 Aug;15:1520-5; Florell SR et al. J. Invest. Dermatol. 2008 Aug;128:2122-5; Larre Borges A et al. Br. J. Dermatol. 2009 Sep;161:536-41; Harland M et al. Hered. Cancer Clin. Pract. 2014 Nov;12:20; Bruno W et al. J. Am. Acad. Dermatol. 2016 Feb;74:325-32; Puig S et al. Genet. Med. 2016 Jul;18:727-36; Taylor NJ et al. J. Invest. Dermatol. 2017 12;137(12):2606-2612; Brand R et al. Cancer. 2018 Sep;124(17):3520-3527). Based on the supporting evidence, this alteration is interpreted as a disease-causing mutation. -
The CDKN2A locus encodes two different gene products, p16INK4a and p14ARF (https://www.ncbi.nlm.nih.gov/books/NBK7030/). This variant is located in the 5' untranslated region of the CDKN2A gene (P16INK4A). A functional study has shown that this variant creates a new translation initiation AUG codon, and translation initiation from this novel site results in a truncated protein, while blocking wild-type protein expression (PMID: 9916806). This variant has been reported in over thirty individuals affected with melanoma (PMID: 9916806, 16397522, 17713569, 18025365, 19523171, 25023876, 25780468, 26581427, 26681309, 26775776, 29263814, 31567591) and has been shown to segregate with melanoma and pancreatic cancer in four different families (PMID: 9916806). This variant has been identified in 6/146754 chromosomes in the general population by the Genome Aggregation Database (gnomAD). Based on the available evidence, this variant is classified as Pathogenic. -
Melanoma, cutaneous malignant, susceptibility to, 2 Pathogenic:1Other:1
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Melanoma and neural system tumor syndrome Pathogenic:1
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Melanoma;C0919267:Ovarian neoplasm Pathogenic:1
ACMG classification criteria: PS3 supporting, PS4 strong, PM2 moderate, PP1 strong -
CDKN2A-related disorder Pathogenic:1
The CDKN2A c.-34G>T variant is located in the 5' untranslated region. This variant corresponds to a deep intronic position in the alternate transcript for this gene that encodes p14ARF (NM_058195.3:c.194-3653G>T). This variant has been reported in individuals with melanoma and segregated within families (Liu et al. 1999. PubMed ID: 9916806; Harland et al. 2000. PubMed ID: 10738302; Andreotti et al. 2016. PubMed ID: 26581427). It has also been reported in an individual with pancreatic adenocarcinoma (Brand et al. 2018. PubMed ID: 30067863). In vitro experimental studies indicate that this variant results in a novel alternative initiator that subsequently leads to decreased translation from the normal start site and ultimately a truncated protein (Liu et al. 1999. PubMed ID: 9916806). In addition, this variant significantly alters transcriptional activity as observed by in vitro reporter assay (Bisio et al. 2010. PubMed ID: 20093296). This variant is reported in 6 of ~147,000 alleles in gnomAD; however, the data quality is questionable and should be interpreted with caution. This variant is interpreted as pathogenic in ClinVar (https://www.ncbi.nlm.nih.gov/clinvar/variation/182414/). This variant is interpreted as pathogenic. -
Melanoma and neural system tumor syndrome;C1835044:Melanoma, cutaneous malignant, susceptibility to, 2;C1838547:Melanoma-pancreatic cancer syndrome Pathogenic:1
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Familial melanoma Pathogenic:1
This variant occurs in a non-coding region of the CDKN2A (p16INK4a) gene. It does not change the encoded amino acid sequence of the CDKN2A (p16INK4a) protein. The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This variant has been observed in individual(s) with familial melanoma (PMID: 9916806, 10738302, 16397522, 17713569, 18025365, 18337833, 19523171). It is commonly reported in individuals of British ancestry (PMID: 9916806, 10738302, 16397522, 17713569, 18025365, 18337833, 19523171). ClinVar contains an entry for this variant (Variation ID: 182414). Studies have shown that this variant alters CDKN2A (p16INK4a) gene expression (PMID: 9916806, 20093296). For these reasons, this variant has been classified as Pathogenic. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at